Masculinity as properly defined is an aspirational and normative style of being and living as a natural-born man that a critical mass of the members of that population applaud. Masculinity may evolve over time and diverge within cultures, but there are trans-historical and trans-cultural aspects that any reasonable man can realistically point to through comparison using deitic adverbs. ("This is masculinity. That is not masculinity.") It is not a heteronormative phenomenon insofar as non-heterosexual males make the same denotations in whatever argot and the interactions between heredity and environment out of which the phenomenon of masculinity arises are visible in mass popular culture. As examples, James Bond, Sean Connery, Conan the Barbarian, and Arnold Schwarzenegger are masculine. When "masculine" is applied to women, the term denotes mannish features (or severe unattractiveness). That is not masculinity.

The fragile trait almost every headass man has. It's so fragile to these fuckers they can't even blink at a god damn purse without thinking their friends are going to make fun of them, and that society is going to view them differently.

GF: "Babe come to Sephora with me I need help choosing a lipstick color that will suit me"
Headass BF: "No I'll just wait outside, just being around Sephora hurts my masculinity haha. I'll be at GameStop calling everyone bro because I'm straight and need to let everyone know that I like pussy, because everybody probably saw me in front of a makeup store and are already starting to think things."
GF: "Bu-But there's no GameStop in this mall"
Headass BF: I know that but you need to understand everybody probably saw me and I need to renew my masculinity."
GF: You're not making any sense.
Headass BF: M A S C U L I N I T Y